REL PDBe PDBe PDBe 2012-04-12 2012-04-17 2012-08-01 2012-09-26 Gating movement in acetylcholine receptor analysed by time-resolved electron cryo-microscopy Unwin N Fujiyoshi Y acetylcholine receptor, freeze-trapping, asymmetric gating, allosteric mechanism Unwin N Fujiyoshi Y Gating movement of acetylcholine receptor caught by plunge-freezing. J.MOL.BIOL. 422 617 634 2012 22841691 doi:10.1016/j.jmb.2012.07.010 4aq5 FULLOVERLAP nicotinic acetylcholine receptor in native postsynaptic membrane from Torpedo marmorata nicotinic acetylcholine receptor in native postsynaptic membrane from Torpedo marmorata 5 subunits 1 0.3 0.3 molecular weight based on amino acid sequence data and attached sugars nicotinic acetylcholine receptor Torpedo marmorata marbled electric ray electric organ electrocyte cells plasma membrane plasma membrane 0.3 0.3
Protein is embedded in postsynaptic membrane isolated from Torpedo marmorata electric organ
pentamer false helical helicalArray 7.0
100 mM sodium cacodylate, 1 mM calcium chloride
300 mesh copper grid with pre-irradiated thick holey carbon support, glow discharged in amylamine atmosphere
 ETHANE 85 120 HOMEMADE PLUNGER
Vitrification carried out at an ambient temperature of 8 degrees C
Vitrified within 10ms of exposure to acetylcholine (applied as the grid is being plunged,using a fine, focussed spray positioned about 1cm above the ethane surface) Blot until applied droplet loses contact with filter paper (indicated by loss of transparency; typically 6s)
Tubular membrane crystals of acetylcholine receptors grow spontaneously from isolated postsynaptic membranes when incubated in low salt buffer at 17 degrees C for two weeks
 JEOL 3000SFF FLOOD BEAM BRIGHT FIELD FIELD EMISSION GUN 300 1.6 0.9 2.0 40000.0 38500.0 OTHER 10 20 10 Objective lens astigmatism was corrected based on appearance of carbon film at 250,000 times magnification
Standard low dose imaging of specimens over holes in the carbon support film
2005-11-01 KODAK SO-163 FILM OTHER 2.5 111 25
All images recorded on film, developed in Kodak d19 developer
1.0 16. Top-entry holder for liquid helium cooled stage (the temperature of the specimen in this holder is usually at 4K)
Alignment and distortion correction of each tube image was done using a segmental Fourier-Bessel method (Beroukhim & Unwin (1997) Ultramicroscopy, 70:57-81) with 50% overlap between successive segments
OTHER 6.2 FSC 0.5 CUT-OFF MRC, and, own, programs
Final maps were calculated from 111 tube images(closed class) and 123 tube images (open class)
Each tube image
 emd_2071.map.gz 1 IMAGE STORED AS FLOATING POINT NUMBER (4 BYTES) 128 128 168 0 0 0 128 128 168 128.0 128.0 168.0 90.0 90.0 90.0 Y X Z -3.90023351 4.90560436 0.0 1.0 1.0 1.0 1.0 1.2 AUTHOR Density map of acetylcholine receptor
::::EMDATABANK.org::::EMD-2071::::
 2BG9 A B C D E FLEXIBLE FIT DireX
Protocol: Maximisation of correlation between experimental densities and atomic model, using a deformable elastic network algorithm. Identical refinement procedures were applied to both density maps. The fits were validated by applying the same refinement procedures to independent density maps calculated from half-datasets
REAL